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Insurance - Narrative (Details) - Special Asbestos and Environmental reserve charges - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Insurance [Line Items] |  |  |  |
Net increase (decrease) in the provision for claims of prior years |  |  | $ 18 | $ 18
Other lines | Property and Casualty Insurance |  |  |  |
Insurance [Line Items] |  |  |  |
Net increase (decrease) in the provision for claims of prior years | $ 18 | $ 18 | $ 18 | $ 18

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- Definition Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred in prior reporting periods and related claims settlement costs. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437 + Details
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